Engine for pneumatic systems



(No Model.)

2 Sheets-Sheet 1 0. L. BROADBENT.

ENGINE FOR PNEUMATIG SYSTEMS.

Patented Aug. 11, 1885.

'u ll N. PETERS. Phnlo-Ulhognphar. Walhinginn. D. C.

(No Model.) 2 Sheets-Sheet 2.

0. L. BROADBENT.

ENGINE FOR PNEUMATIC SYSTEMS.

No. 324,076. Patented Aug. 11, 1885.

N. PETERS. PholvLilMgmphen Wnhingtum D. C.

UNITED STATES PATENT Q FICE.

CHARLES L. BROADBENT, OF NE\V YORK, N. Y., ASSIGNOR TO THE GEORGE F. BLAKE MANUFACTURING COMPANY, OF BOSTON, MASSACHUSETTS.

ENGINE FOR PNEUMATIC SYSTEMS.

SPECIFICATION forming part of Letters Patent No. 324,076, dated August 11, 1885,

Application filed March 31, 1884. (No model.)

To all whom it may concern:

Be it known that 1, CHARLES L. BROAD-' BENT, of the city and State of New York, have invented an Improvement in Engines for Pneumatic Systems, of which the following is a specification.

Pneumatic tubes are made use of to convey packages from one place to another, and holders or cases containing written messages have also been transmitted through such tubes. It is usual to have an engine and air-pump at one station and to have two tubes extending to the distant station and there connected, one tube being for holders going in one direction I5 and the other for holders going in the opposite direction. In order to obtain the greatest rapidity in the movement of the carrier it is advantageous to exhaust the air from one end of one tube and to force air under pressure into the other tube, so that the same may follow up and give motion to the holder or package placed in the tube, the exhaust acting at one side and the pressure at the other side of the holder. In some instances an engine and air-pump are placed at each station, the connections being made so that air is forced into one end and exhausted from the other end of each tube, and so that the air will travel in one tube in one direction and in the other tube in the other direction. My improvements are adapted to either of the aforesaid systems.

In constructing engines for these pneumatic systems it is very important to guard against delay in case of any part of either engine requiring repair or repacking, especially where the systems are at work both day andnight. I make use of two engines, each having two air-pumping cylinders. Each of these cylin- 0 ders is provided with ordinary induction and eduction valves, and all the cylinders are connected by branch pipes to two main pipes, one of which leads to' or is a continuation of the suction-pipe in the pneumatic system, and the 5 other leads to or is a continuation of the compressed-air pipe in such pneumatic system, and in each branch pipe there is a lateral opening to the external air and two valveseats and avalve. Vhen the valve is pressed to one seat it closes the opening to the external air. When it is pressed upon the other seat it closes the branch pipe between the pump and the main pipe and opens the lateral opening to the external atmosphere. By properly adjusting the valves in the respective branch pipes either one of the air-pumps can be used to force air into the pneumatic system or to exhaust the air'from that system; and if either pump has to be stopped it can be done without deranging the action of the other pumps or of the pneumatic system, the valve only requiring adjustment. By this construction either air-cylinder can be run for compression or exhaust, as the circumstances may require; and I arrange the pipes and valves 6 that connect the air-pumps to the system of pneumatic tubes in such a manner that either one or more of the pumps can be used as aircompressors, and either one or more as exhausters, and either one or more can be stopped or thrown out of action.

In the drawings, Figure 1 is a plan of the engines, air-cylinders, pipes, and valves. The pipe P is partially removed to more clearly show the other parts. Fig. 2 is an elevation of one of the air-cylinders, and a section of the valve-seats, and of part of the branch pipe leading from the pump-valve chamber to the compression-pipe of the pneumatic system; and Fig. 3 is an end view of the aircylinder 8 and a similar section of part of the branch pipe between the induction-chamber of the pump and the exhaust-pipe of the pneumatic system.

The steam cylinders A B are provided with 3 connecting-rods A B from the cross-heads to the cranks 0 upon the shaft 0, and this shaft has a fly-wheel, G the cranks being at right angles, so as to render the movements of the engines uniform and avoid a dead-center. I 0 remark that the engines may be of any desired character, my improvements not being limited to theengines shown. The piston-rods a 1) preferably pass from the pistons of the steamengines to the pistons in the respective air- 5 cylinders E F E F. so as to be direct-acting.

In air-pumps of this class the cylinder-heads Z are usually hollow, with a partition and induction and eduction valves.

The exhaust-pipe P of the pneumatic sys- 109 tem is connected by the branch pipes g to the ainpassagesy on the tops of the air-pumps, and the compressed-air pipe T is connected by the branch pipesh/to the ainpassages h, below the air-pumps. In each ofthese branch pipes there are seats, a lateral opening, and a valve, as next described.

The stop-valves are all made in a similar manner. Each one has a diaphragm across from one side to the other, and in it is a seat, 8. There is an opening at one side of the case and the valvescat t. The valve .9 is upon the spindle s that passes through the packinggland s", and is provided with a screw-thread and a bridge, 5, forming a nut for the screw, and a hand-wheel, to rotate the spindle. The valve is between the seats 8 and i. \Vhen pressed upon the seat 25, the external atmosphere is excluded from the branch pipe and pump, and a passage opened to the pump from the pneumatic system through the stop-valve seat 8. \Vhen the valve is pressed against the seats, the passage through the stop-valve is closed, but the seat 6 is opened. External air is admitted through this seat t to pass into the pump at that valve which is used upon the exhaust-pipe, so that the external air passes to the pump instead of the air being exhausted from the pipe I. At that valve which is between the pipe T and pump the air of the pump passes into the external atmosphere instead of going into the pipe T, when the valve is upon the seat .5 and the seat t is open.

The tube 1. of the pneumatic system is connected, through the branch pipe 9 and stopvalve Q, with the cylinder E, and through the branch pipe and stop-valve R with the cylinder F. The tube T of the pneumatic system is connected by the branch pipe and stopvalve U with the cylinder E. and by the branch pipe and stop-valve V with the cylinder F.

The valves in the branch pipes to the cylinders E F are marked Q, R, U, and V, re spectively.

When the valves Q and It are opened to the external atmosphere, and the valves U and V are closed to the external atmosphere, the cylinders E F will draw in the atmosphere at Q, R and force it into the tube T of the pneumatic system. At the same time the valves Q R of the cylinders E F should be closed to the external atmosphere, and the valves V U opened to the external atmos phere, and the atmosphere will be drawn out of the pipe 1 in the pneumatic system and discharged at U V into the external atmosphere; hence the cylinders E F will compress the air, and the cylinders E F will exhaust the air, in the pipes of the pneumatic system.

It is to be understood that the tubes P and v T extend to the distant station; that the air is traveling in them, as indicated by the an rows, and that the usual openings and valves are provided for inserting and discharging or delivering the holders. Usually, there are tanks or holders near the engine, one into which the air is forced and from the other of which it is exhausted. It is also to be understood that it is preferable to place two en gines and air-pumps side by side at one station, as shown in Fig. l, the pipes being connected, as shown, and for long united tubes there are by preference double engines, such as shown in Fig. 1, at each station, and that the pipeT at one station is connected up so as to force ai r into the exhaust-pipe P from the other station. These modes of connecting the pipes from one station to the other in pneumatic systems being known do not require further description.

If desired, the cylinders E F may be withdrawn from work by stopping their engine, in which case the valve Q can be opened to the external atmosphere and U closed, and R closed and V opened to external atmosphere, in which case the cylinder E will draw in external atmosphere at Q and force the same into the pipe T of the pneumatic system, and the cylinder F will exhaust from P and discharge the same into the atmosphere at V. sitions of the valves may be reversed, and the cylinder F will then compress and E exhaust. The cylinders E F may be put out of operation, and the cylinders E F only be used; or, if desired, three cylinders may be used, two acting as exhausters and one as a compressor, or the reverse.

By this improvement I am able to employ whatever force is necessary to compress and exhaust the atmospherein the pneumatic sys tem, and to throw out of action any one or more of the cylinders, and to use either cylinder as an exhauster or a compressor.

I claim as my in vention l. The combination, with two air cylinders, pistons, and valves, of the. pipes P T and. their branch connections, one for compressed air and the other for exhaust in a pneumatic system, and the valves Q, R,U, and V, each constructed, substantially as specified, so as to either close the pneumatic pipe and open the branch to the external atmosphere, or the reverse, and thereby provide for either of the cylinders to act as an air-compressor or an air-exhauster, substantially as set forth.

2. In a pneumatic apparatus operated by compressed air and suction, the combination ot'twosteam-engines, connectingrods, cranks, and lly-wheels, and four air-cylinders, the compressed air-pipe T, and branch conneetions]z/, the exhaustpipe P, and branch connections 1 and the valves Q It U V and QR U V, eonstructed and arranged substantially as specified, wherebythe air-cylinders can be used for either compression or exhaust, as required, substantially as set forth.

Signed by me this 25th day of March, A. D. 1884-.

(1. L. I-lROAlHaENT.

XVitnesses:

(ino. T. PINOKNEY, \Vi L'LTA u G. Mo'r'r.

The po- IIO 

